This invention relates to a rice cooking pot for use in cooking rice in a microwave oven.
A typical prior art rice cooking pot of this type comprises a container body for holding rice, an inner lid for covering the opening of the container and an outer lid to be placed over the inner lid and press-fitted on the container. The inner lid usually has vent holes for venting steam.
Tasty boiled rice is obtainable by cooking rice with a weak heating power at the initial stage, with a strong heating power at the intermediate stage and with a weak heating power again at the last stage. More specifically, in the initial stage of cooking, the heating power should be increased gradually until the entirety of the rice is heated sufficiently with the boiled water circulating through the rice grains. When the entire amount of rice has been heated sufficiently, the heating power is increased to the maximum to promote gelatinization of the rice. When the rice grains expand and turn into a gelatinous, colloidal state wherein no convection of boiled water occurs, the heating power is reduced to allow the boiled rice to settle by its own heat while absorbing water sufficiently.
When cooking rice in a microwave oven, it is preferable to heat rice following the above three stages. But no microwave oven is available to date which can automatically change its output and thus the heating temperature in stages. Also, heating with a microwave oven has a feature in that the material to be heated tends to be heated quickly at its peripheral part and more slowly at the central part thereof.
Thus, when cooking rice in a microwave oven, strong heating power is applied from the beginning because the output of microwave oven is constant. Thus, water begins to boil at the peripheral portion before the entire part of rice is heated sufficiently. Thus, the water content reduces rapidly before the rice is gelatinized sufficiently. Moreover, the rice cannot be gelatinized evenly. Insufficiently gelatinized rice is hard and not tasty.
In order to avoid this problem, it was an ordinary practice to stop heating when the water boils and wait until the heat is distributed evenly over the entire area of rice and then to resume heating. But this is not only troublesome but also has a problem in that when the heating is stopped, the speed at which the rice is gelatinized slows down or the gelatinization stops completely because of the reduced heating temperature. The subsequent reheating cannot gelatinize rice to such a level that is attainable by continuous heating. The rice thus cooked is hard and not tasty.
It is an object of this invention to provide a rice cooking pot which makes it possible to heat rice over the entire part thereof at the initial stage of cooking in a microwave oven.